Chromatogram data processing system

Patent metadata

Field	Value
Publication number	US-10802005-B2
Application number	US-201414914706-A
Country	US
Kind code	B2
Filing date	May 20, 2014
Priority date	Sep 2, 2013
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

A chromatogram data processing system having an impurity detector including a differential chromatogram creator, a purity curve creator and a determiner. The differential chromatogram creator calculates a differential coefficient of an absorbance spectrum with respect to wavelength at a local maximum or local minimum absorption wavelength of the target component, and creates a differential chromatogram which shows a temporal change of the differential coefficient. The purity curve creator creates a purity curve which shows a temporal change of the difference between the degree of similarity of a spectrum on the target peak to a reference spectrum and a threshold of the degree of similarity which is determined taking into account the influence of noise components. The differential chromatogram and the purity curve are displayed on a display unit in a superposed form on a wavelength chromatogram created by a wavelength chromatogram creator.

First claim

The invention claimed is:

1. A chromatogram data processing system, comprising:
a) a three-dimensional data storage section for storing three-dimensional chromatogram data with time, wavelength and absorbance as dimensions;
b) a wavelength chromatogram creator for extracting, from the three-dimensional chromatogram data, a set of data obtained at a specific wavelength which is an absorption wavelength of a target component and for creating a wavelength chromatogram showing a relationship between the time and the absorbance at the specific wavelength;
c) a peak detector for detecting a peak of the created wavelength chromatogram;
d) a processor configured to create graphs showing a presence or absence of at least one impurity in the detected peak by performing two or more detection methods on the three-dimensional chromatogram data sequentially in one analyzing process, wherein the two or more detection methods are designed to enable to detect different impurity, respectively, and are applied to a same peak of the three-dimensional chromatogram data; and
e) a display unit for displaying the graphs that are different from each other obtained by the two or more detection methods in a superposed form on the wavelength chromatogram to determine a presence or absence of the at least one impurity in the detected peak,
wherein the two or more methods are selected from a group consisting of a degree-of-matching determination method in which a degree of matching between an absorbance spectrum at time T 0 corresponding to a peak top of a target peak on the wavelength chromatogram and an absorbance spectrum at an arbitrary time T before or after T 0 is calculated, a differential spectrum method in which a differential coefficient of an absorbance spectrum with respect to wavelength at a local maximum or local minimum absorption wavelength of the target component is determined, and if a peak is located in a waveform of a differential chromatogram which shows a temporal change of the differential coefficient, it is determined that an impurity is contained, and a purity determination method in which the presence or absence of an impurity is determined by comparing a degree of similarity between a spectrum on a target peak and a reference spectrum, with a degree of similarity of these two spectra which is determined taking into account an influence of noise components.

2. The chromatogram data processing system according to claim 1 , further comprising:
f) an input section for selecting the two or more detection methods to be used by the impurity detector, or for inputting a parameter to be set in the two or more detection methods.

Assignees

• Shimadzu Corp

Inventors

• Mishima Kenichi
• Kamata Etsuho
• Miura Hiroshi
• Mito Yasuhiro
• Yanagisawa Toshinobu

Classifications

• G01N30/8651

  Recording, data aquisition, archiving and storage · CPC title

• G01N30/74

  Optical detectors {(measurement of intensity, velocity, spectral content, polarisation, or phase of infrared, visible or ultraviolet light G01J)} · CPC title

• G01N30/8624 Primary

  Detection of slopes or peaks; baseline correction · CPC title

• G01N30/8689

  Peak purity of co-eluting compounds · CPC title

• G01N30/8675

  Evaluation, i.e. decoding of the signal into analytical information (for analysis of specific compounds see also G01N30/88 and subgroups of G01N33/00; chemical libraries per se C40B) · CPC title